I suspect that Putin believed that he could continue to sell his oil to Europe even while ravaging one of the nations there. Guess he miscalculated our capacity for change, and our outrage as well.
This isn't like the invasion of Georgia or Crimea
Putin's unprovoked invasion of Ukraine is so shocking precisely because of it's barbarity, it's criminality, and it's indiscriminate use of violence against civilians.
Nothing even remotely like it has been seen in Europe since Hitler was in power.
Until February 2022, Europeans thought Putin could be engaged with. I think their eyes have been opened, and they consider Putin an irredeemable war criminal, a dangerous war monger, a duplicitous gangster whose word cannot be trusted.